Evaluation of SO2 and NO2 concentration levels in Vilnius (Lithuania) using passive diffusion samplers

Sometimes it is useful to use diffusion sampler first introduced by Palmes et al. (1976) in the field of occupational hygiene and used for indoor NO2 measurement where the sorbed amount must be proportional to the ambient concentration of the gas. The diffusion samplers for the outdoor environment — ambient SO2 and NO2 measurements in both urban and rural areas are widely described (Campbell, 1988; Ferm, 1991; Campbell et al., 1994; Carmichael et al, 1995). The aim of this study was to evaluate SO2 and NO2 concentration levels in the main district types of Vilnius such as cross roads, dwelling regions, rest places and background level using rather cheap type of diffusion sampler.